Papers by Keyword: TiH₂ Powder

Abstract: The main aim of this research was to investigate the influence of processing parameters on the me-chanical properties and morphology of porous STS:TiH₂ composites made by using spark plasma sintering method. Mechanical parameters and structural analysis of the fabricated composite have been investigated by Rockwell hardness, density tester, optical microscope, XRD and FE-SEM. In particular the porous stainless steel (STS) and titanium hydride TiH₂ composites materials with op-timal ratio were prepared with using additional hollow glass microsphere and water glass for con-trolling of the porosity degree. It is found, that the porosity degree depended on addition of TiH₂ and hollow glass additive, resulting to modification of the pore shape and size. I was shown that the dispersion of STS/TiH2 composite which sintered by spark plasma sintering method without pressure result to increasing of mechanical properties (hardness and density). According to obtained results, the addition of TiH2 powder into STS improves the mechanical property of the synthesized specimens especially the specimens with addition 20 wt% and 50 wt% of TiH₂ demonstrated high hardness values and good density.

Abstract: Powder Injection molding (PIM) is a cost-effective process for the fabrication of complex shaped parts, and has a great potential in many applications. In this work, an improved wax-based binder was developed for the powder injection molding of TiH₂ powder fabricated by recycling of Ti chip. Fine TiH₂ powders of about 350 nm in particle size were produced by attrition milling of Ti chip in less than five minutes, resulting from simultaneous self-propagating High temperature Synthesis (SHS) and fracturing. TiH₂ feedstock, a mixture of binder and powders, was fabricated with critical powder loading of 68 vol.%. The rheological characteristics of the feedstock were investigated for subsequent processing step. Viscosity of the feedstock showed pseudo-plastic flow behavior and to optimize injection molding parameter, in-mold rheology curve was generated. The results indicated that the recycled TiH₂ feedstock can be used for the fabrication of the complex shaped parts with good shape.

Abstract: Nano-TiC powders were fabricated for mechanical alloying (MA) by shaker mill using the TiH2 powders mixed carbon powder. For mechanical alloying, titanium hydride was easily breaking alloy and easily decomposed titanium particles and hydrogen gas. The decomposition titanium powders in TiH2 powders were very fine particle size and unstable phase. And it easily reacted to carbon ;(TiH2 + C 􀃆 TiC + H2). The effects of mechanical allyoing, morphology, phase and particle size were evaluated with X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), TG/DTA and particle size analyzer. As-milled powders for 10 hours were successfully synthesized powders of TiC phase, mean particle 300nm size. And as-milled powder for 1 hour was included unstable phase, was annealed for 1 hour at 400°C-1300°C in 1x10-3torr vacuum atmosphere. Unstable phase was changed to recrystallize phase by heat treatment. After heat treatment for 1hour using as-milled powders, it was included many types of titanium oxide at temperature below 1000°C, was formed single phase of TiC at temperature over 1000°C.